Update on the JSE’s Equity Market halt

August 25, 2011

Johannesburg, 24 August 2011: Further to our communication issued yesterday, 23 August, regarding yesterday’s half an hour halt to trading on the JSE’s equity market, MTN (the JSE’s international links service provider) has indicated that the cause of the loss of connectivity was due to multiple link flaps occurring between 15h32 and 15h41 on the primary telecommunications link over which the JSE Equity Market public data flows.

These multiple link flaps originated in the corresponding International carrier network in Europe. Due to the very short duration of these interruptions, the JSE multicast traffic (public data) would not switch to one of the other alternate paths automatically as would be the case with a longer duration interruption. This resulted in the JSE Equity Market clients missing approximately 177 000 public data messages. This necessitated the JSE halting the Equity Market for just over 30 minutes on 23 August to allow clients to recover the missed public data in order to ensure JSE clients had an accurate and up to date picture of the current state of the Equity Market.

Interruptions of this nature require manual intervention to reroute the traffic if they persist, however in this case, the corresponding International carrier network in Europe recovered before any manual intervention could be initiated.

MTN indicated that this failure did not have an impact on other customers of MTN.

About JSE Limited
As South Africa’s only full service securities exchange, the JSE connects buyers and sellers in four different financial markets, namely equities, equity derivatives, commodity derivatives and interest rate instruments. The JSE Ltd offers the investor a truly first world trading environment, with world class technology, surveillance and settlement in an emerging market context. It is amongst the top 20 largest equities exchanges in terms of market capitalisation in the world.
For further information, please visit www.jse.co.za  


Victoria Williams / Renata Da Silva
Corporate Communications Consultants
Tel: 011 463 2198 /
Email: victoria@corpcom.co.za  / renata@corpcom.co.za